A method for injecting a fuel-air mixture into a combustion chamber is known from the document U.S. Pat. No. 6,038,863.
Premix burners, depending on the premixing quality, allow the NOx emissions from gas turbines to be greatly reduced. One problem in this context, however, is the relatively narrow operating range of premix burners. An additional flame is required for part-load operation even when swirl stabilization with vortex breakdown is employed, as are known, for example, in double-cone burners from U.S. Pat. No. 4,932,861 or in double-cone burners with downstream mixing section as described, for example, in EP 0704657. This part-load flame or pilot flame is generally diffusive in nature and should ideally be in as close proximity as possible to the (premix) main flame. Furthermore, it is necessary to take aerodynamic measures to avoid recirculation of fuel/air mix in the pilot fuel system during premix operation, since this mix can ignite and can thereby lead to overheating of the fuel lines.
DE-A1-44 24 597 discloses a combustion device. This combustion device is especially suitable for a gas turbine and comprises a combustion chamber with a number of burners operating in parallel. Liquid or gaseous fuel is supplied to these burners from the outside by means of replaceable plug-in fuel lances by way of corresponding liquid fuel supply ducts and/or gas supply ducts. Adjustable throttle locations are provided in the individual fuel lances of the burners for simple adjustment of the fuel distribution in the liquid fuel supply ducts or gas supply ducts.
DE-A1-195 45 310 discloses a premix burner. This premix burner for mixture of fuel and combustion air essentially comprises at least two partial cone shells with associated partial cone axes and inlet ducts for the combustion air. The premix burner is formed essentially of a straight hollow cone that is delimited by an outer cone jacket and an inner cone jacket and in that at least two inlet ducts are arranged tangentially to the inner cone jacket and arranged along a straight cone jacket line of the cone jacket. The partial cone axes of the partial cone shells formed in this way lie on a common cone axis.
U.S. Pat. No. 5,782,626 discloses an atomizer nozzle. In this airblast atomizer nozzle for operation of a burner that can be operated with liquid and gaseous fuels, the middle wall between the inner and outer air ducts is held by inner and outer support elements that have a sliding seat and can be formed as swirl blades. The atomizing edges of the airblast nozzle are angled in the direction of the nozzle axis. The nozzle is characterized by its small dimensions, low pressure loss and low tendency to coking.